Re: [PATCH v4 0/3] Fix regression introduced by disabling accelerated scrolling in fbcon

[Daniel Vetter <daniel@ffwll.ch>]

On Wed, Feb 02, 2022 at 02:55:28PM +0100, Helge Deller wrote:
> This series reverts two patches which disabled scrolling acceleration in
> fbcon/fbdev. Those patches introduced a regression for fbdev-supported graphic
> cards because of the performance penalty by doing screen scrolling by software
> instead of using existing 2D hardware acceleration.
> 
> The third patch introduces a new config option
> CONFIG_FRAMEBUFFER_CONSOLE_LEGACY_ACCELERATION, which -if enabled- switches
> fbcon to utilize the bitblt and fillrect hardware acceleration in the
> framebuffer console. If disabled, such acceleration will not be used, even if
> it is supported by the graphics hardware driver.
> 
> This series is being discussed on linux-fbdev and dri-devel mailing lists.
> 
> Updates in v3:
> - respin with fixes to build rotation code
> 
> Updates in v4:
> - changed the Kconfig option and Kconfig help text
> 
> Helge Deller (3):
>   Revert "fbdev: Garbage collect fbdev scrolling acceleration, part 1
>     (from TODO list)"
>   Revert "fbcon: Disable accelerated scrolling"
>   fbcon: Add option to enable legacy hardware acceleration

Applied to drm-misc-fixes, thanks for the patches.

Cheers, Daniel

> 
>  Documentation/gpu/todo.rst              |  24 -
>  drivers/video/console/Kconfig           |  20 +
>  drivers/video/fbdev/core/bitblit.c      |  16 +
>  drivers/video/fbdev/core/fbcon.c        | 557 +++++++++++++++++++++++-
>  drivers/video/fbdev/core/fbcon.h        |  72 +++
>  drivers/video/fbdev/core/fbcon_ccw.c    |  28 +-
>  drivers/video/fbdev/core/fbcon_cw.c     |  28 +-
>  drivers/video/fbdev/core/fbcon_rotate.h |   9 +
>  drivers/video/fbdev/core/fbcon_ud.c     |  37 +-
>  drivers/video/fbdev/core/tileblit.c     |  16 +
>  drivers/video/fbdev/skeletonfb.c        |  12 +-
>  include/linux/fb.h                      |   2 +-
>  12 files changed, 753 insertions(+), 68 deletions(-)
> 
> -- 
> 2.34.1
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch